PORT ST. LUCIE, Fla. -- Forget Opening Day, Johan Santana's tender elbow might keep the Mets' ace from making his first start until the second series of the season.

Santana has yet to pitch in a spring training game for New York, which lost 15-4 to the St. Louis Cardinals on Tuesday, and pitching coach Dan Warthen indicated the left-hander's schedule would put him on track to start the Mets' fifth game.

The two-time Cy Young winner is tentatively set to make his spring debut March 18, Warthen said.

Santana hasn't had a bullpen session since Sunday, a day before he was supposed to return to New York for precautionary tests. After throwing, the Mets canceled the trip and Santana said he felt OK.

Santana is scheduled to throw off a bullpen mound Wednesday.

Doctors have told Santana that an irritated triceps tendon is causing the discomfort in his elbow, but Warthen said Santana didn't appear to be favoring anything during his bullpen session Sunday.

The Cardinals' Kyle Lohse, meanwhile, took another step toward being ready for the start of the season. In his second outing of spring training, Lohse gave up three hits in 3 2/3 innings.

"If you are pitching in the fourth inning right now, you have to feel good about it," said Lohse, who allowed four runs and four hits in two innings last week. "You're not going out and using up all your pitches early. That's the plan, to be aggressive and throw strikes."

The Cardinals scored six times in the first three innings, then tacked on seven more runs in the fourth to go up 13-0. Left fielder Chris Duncan, who was limited last year because of a neck injury, hit a three-run homer off Freddy Garcia in the first then tripled to score Albert Pujols in the third.

Duncan went 4-for-4 with five RBIs and three runs before being replaced in the sixth inning.

"What a bomb," La Russa said of Duncan's home run. "He had just great swings all day."

Garcia, a contender for the fifth spot in the Mets rotation, struggled to find command on his fastball for the second straight outing, also gave up a solo shot to Allen Craig in the second inning.

The right-hander exited after two innings, having given up four runs and three hits, but said he felt more comfortable than he did Friday when he allowed four runs while getting just two outs.

"If I can't locate my fastball, I don't have a chance, but I definitely feel better than last week," said Garcia, who is returning from shoulder injuries that limited him the last two seasons. "I'm not happy about four runs in two innings, but I will keep working and try to better locate my fastball."

Pujols had a two-run double and scored three runs for St. Louis, which finished with 15 hits.

Marlon Anderson and catcher Robinson Cancel each went 2-for-3 with an RBI for the Mets. New York didn't score until the sixth inning when Anderson doubled to score Cancel.

"It was one of those days that you think about books to read," Mets manager Jerry Manuel said.

The Mets lost 15 players to the World Baseball Classic, including 11 from the 40-man roster, but Manuel didn't use that as an excuse Tuesday.

"That's a tough thing for us, but what we have to do, we have enough pitching here, we have to get that right," Manuel said.